[CSS Grid Layout] Support calc() breadth track size

The RenderGrid support for calc() was already there but we had to add also the CSSComputedStyle support. According to the specs, http://dev.w3.org/csswg/css-grid/#resolved-track-list, we must show the used value. This change also brings several new tests.

BUG=297689

Review URL: https://codereview.chromium.org/23472008

git-svn-id: svn://svn.chromium.org/blink/trunk@161787 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix crash when interpolating auto shape values

The CSS value "auto" was not handled correctly for animation of CSS
properties shape-inside or shape-outside. Internally this value is stored
as a null ShapeValue pointer and led to a null deref.
This patch fixes the deref and correctly interprets null as CSSValueAuto.

Review URL: https://codereview.chromium.org/68563002

git-svn-id: svn://svn.chromium.org/blink/trunk@161788 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move CSSSelectorWatch related code out of recalcStyle methods

Instead of having checks all over the code we can refactor them into methods.

Review URL: https://codereview.chromium.org/68183007

git-svn-id: svn://svn.chromium.org/blink/trunk@161789 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Reject percentage values for outline-offset during CSS parsing

Percentages in outline-offset are not properly implemented, attempting
to use them will hit an assert in debug. There is no specification for
percentages in outline-offset [1]. Allowing percentages in the CSS
parser is likely an accidental change [2] and should be removed.

[1] http://www.w3.org/TR/css3-ui/#outline-offset
[2] http://src.chromium.org/viewvc/blink/trunk/WebCore/css/CSSParser.cpp?r1=66615&r2=66614&pathrev=66615

Review URL: https://codereview.chromium.org/66553009

git-svn-id: svn://svn.chromium.org/blink/trunk@161791 bbb929c8-8fbe-4397-9dbb-9b2b20218538